(Adds details)

Nov 6 (Reuters) - Irish consumer healthcare company Perrigo Co Plc said it would acquire Belgium's Omega Pharma NV for 2.48 billion euros ($3.11 billion), excluding debt, to expand its over-the-counter products portfolio.

Perrigo said it would also take on 1.1 million euros of debt from privately held Omega.

Over-the-counter drugs offer lower margins than prescription drugs but demand for them is usually higher because they are cheaper.

Omega sells prescription-free medicines, healthcare products and personal care items such as wart treatments and suntan lotions over the counter.

Reuters reported in July that Omega, which was taken private by Chief Executive Mark Coucke and private equity firm Waterland in 2011, hired Morgan Stanley to look at a potential sale.

Perrigo said on Thursday it would place about 5 million shares, representing 25 percent of the equity value of the deal, with Coucke and fund the rest through cash and debt.

Perrigo had 133.9 million shares outstanding as of Sept. 27.

The Irish company said the deal, which was expected to close in the first quarter of 2015, would immediately add to adjusted earnings.

Perrigo said it had secured a 1.75-billion-euro credit facility from J.P. Morgan and Barclays, who were also its financial advisers for the deal.

Freshfields Bruckhaus Deringer was Perrigo's legal adviser.

Morgan Stanley was Omega's financial adviser and Allen & Overy its legal adviser.

Perrigo's shares were down about 1 percent in light trading before the bell. The stock closed at $158.50 on the New York Stock Exchange on Wednesday.

($1 = 0.7981 euro) (Reporting by Ankur Banerjee in Bangalore; Editing by Kirti Pandey)